skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: GAS-PASS/H : a simulation code for gas reactor plant systems.

Abstract

A simulation code for gas reactor plant systems has been developed. The code is intended for use in safety analysis and control studies for Generation-IV reactor concepts. We developed it anticipating an immediate application to direct cycle gas reactors. By programming in flexibility as to how components can be configured, we believe the code can be adapted for the indirect-cycle gas reactors relatively easy. The use of modular components and a general purpose equation solver allows for this. There are several capabilities that are included for investigating issues associated with direct cycle gas reactors. Issues include the safety characteristics of single shaft plants during coastdown and transition to shutdown heat removal following unprotected accidents, including depressurization, and the need for safety grade control systems. Basic components provided include turbine, compressor, recuperator, cooler, bypass valve, leak, accumulator, containment, and flow junction. The code permits a more rapid assessment of design concepts than is achievable using RELAP. RELAP requires detail beyond what is necessary at the design scoping stage. This increases the time to assemble an input deck and tends to make the code slower running. The core neutronics and decay heat models of GAS-PASS/H are taken from the liquid-metal version ofmore » MINISAS. The ex-reactor component models were developed from first principles. The network-based method for assembling component models into a system uses a general nonlinear solver to find the solution to the steady-state equations. The transient time-differenced equations are solved implicitly using the same solver. A direct cycle gas reactor is modeled and a loss of generator load transient is simulated for this reactor. While normally the reactor is scrammed, the plant safety case will require analysis of this event with failure of various safety systems. Therefore, we simulated the loss of load transient with a combined failure of the bypass valve to open and with the bypass valve open. The stability and the asymptotic state of the plant is of interest from the safety standpoint. GAS-PASS/H simulates the transient reasonably well. However, one can see that at a steady state the mechanical power delivered to the generator is less than 10 percent of the reactor power. This is less than the typical value of greater than 40 percent for a GTMHR. This result suggests that some work is needed to optimize the turbomachine efficiencies through better choice of turbomachine steady state reference operating points.« less

Authors:
; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
943419
Report Number(s):
ANL/NE/CP-113708
TRN: US0900398
DOE Contract Number:  
DE-AC02-06CH11357
Resource Type:
Conference
Resource Relation:
Conference: 2004 International Congress on Advances in Nuclear Power Plant (ICAPP '04); Jun. 13, 2004 - Jun. 17, 2004; Pittsburgh, PA
Country of Publication:
United States
Language:
ENGLISH
Subject:
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS; ACCIDENTS; CONTAINMENT; CONTROL SYSTEMS; DEPRESSURIZATION; FLEXIBILITY; NUCLEAR POWER PLANTS; PROGRAMMING; SAFETY; SAFETY ANALYSIS; SHUTDOWN; SIMULATION; STABILITY; TRANSIENTS; VALVES

Citation Formats

Vilim, R. B., Mertyurek, U., Cahalan, J. E., Nuclear Engineering Division, and Texas A&M Univ. GAS-PASS/H : a simulation code for gas reactor plant systems.. United States: N. p., 2004. Web.
Vilim, R. B., Mertyurek, U., Cahalan, J. E., Nuclear Engineering Division, & Texas A&M Univ. GAS-PASS/H : a simulation code for gas reactor plant systems.. United States.
Vilim, R. B., Mertyurek, U., Cahalan, J. E., Nuclear Engineering Division, and Texas A&M Univ. Thu . "GAS-PASS/H : a simulation code for gas reactor plant systems.". United States.
@article{osti_943419,
title = {GAS-PASS/H : a simulation code for gas reactor plant systems.},
author = {Vilim, R. B. and Mertyurek, U. and Cahalan, J. E. and Nuclear Engineering Division and Texas A&M Univ.},
abstractNote = {A simulation code for gas reactor plant systems has been developed. The code is intended for use in safety analysis and control studies for Generation-IV reactor concepts. We developed it anticipating an immediate application to direct cycle gas reactors. By programming in flexibility as to how components can be configured, we believe the code can be adapted for the indirect-cycle gas reactors relatively easy. The use of modular components and a general purpose equation solver allows for this. There are several capabilities that are included for investigating issues associated with direct cycle gas reactors. Issues include the safety characteristics of single shaft plants during coastdown and transition to shutdown heat removal following unprotected accidents, including depressurization, and the need for safety grade control systems. Basic components provided include turbine, compressor, recuperator, cooler, bypass valve, leak, accumulator, containment, and flow junction. The code permits a more rapid assessment of design concepts than is achievable using RELAP. RELAP requires detail beyond what is necessary at the design scoping stage. This increases the time to assemble an input deck and tends to make the code slower running. The core neutronics and decay heat models of GAS-PASS/H are taken from the liquid-metal version of MINISAS. The ex-reactor component models were developed from first principles. The network-based method for assembling component models into a system uses a general nonlinear solver to find the solution to the steady-state equations. The transient time-differenced equations are solved implicitly using the same solver. A direct cycle gas reactor is modeled and a loss of generator load transient is simulated for this reactor. While normally the reactor is scrammed, the plant safety case will require analysis of this event with failure of various safety systems. Therefore, we simulated the loss of load transient with a combined failure of the bypass valve to open and with the bypass valve open. The stability and the asymptotic state of the plant is of interest from the safety standpoint. GAS-PASS/H simulates the transient reasonably well. However, one can see that at a steady state the mechanical power delivered to the generator is less than 10 percent of the reactor power. This is less than the typical value of greater than 40 percent for a GTMHR. This result suggests that some work is needed to optimize the turbomachine efficiencies through better choice of turbomachine steady state reference operating points.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2004},
month = {1}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share: